Heuchera plant named ‘TNHEULS’

ABSTRACT

A new and distinct  Heuchera  plant characterized by better sun tolerance compared to other known yellow foliage cultivars, white flowers on medium short spikes, full crown of lime-green spring leaves that turn to yellow in the sun, medium-small mounding habit, and excellent vigor.

Botanical denomination: Heuchera hybrid.

Variety designation: ‘TNHEULS’.

Trademark designation: Lemon Supreme™.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Heuchera and given the cultivar name of ‘TNHEULS’. Heuchera is in the family Saxifragaceae. Heuchera ‘TNHEULS’ originated as a controlled cross using Heuchera B447-3′, a proprietary, unpatented, unnamed plant as the seed parent, and Heuchera ‘B446-1’, a proprietary, unpatented, unnamed plant as the pollen parent. These parents are part of a breeding plan to produce a sun tolerant yellow to lime foliage Heuchera.

Compared to the seed parent, Heuchera ‘B447-3’, the new cultivar has a larger crown and habit.

Compared to the pollen parent, Heuchera ‘B446-1’, the new cultivar has shorter inflorescences and a larger habit.

Compared to Heuchera ‘Lemon Chiffon’, U.S. Plant Pat. No. 19,033, the new cultivar has improved sun tolerance, thicker leaves, and larger flowers that are white rather than light coral pink.

This new Heuchera is uniquely distinguished by:

-   -   1. better sun tolerance compared to other known yellow foliage         cultivars,     -   2. white flowers on medium short spikes,     -   3. full crown of lime-green spring leaves that turn to yellow in         the sun,     -   4. medium-small mounding habit, and     -   5. excellent vigor.

This new cultivar has been reproduced only by asexual propagation (tip cuttings and micropropagation using growing tips). Each of the progeny exhibits identical characteristics to the original plant. Asexual propagation by cuttings and tissue culture using standard micropropagation techniques with terminal and lateral shoots, done in Canby, Oreg., shows that the foregoing characteristics and distinctions come true to form and are established and transmitted through succeeding propagations. The present invention has not been evaluated under all possible environmental conditions. The phenotype may change with variations in environment without a change in the genotype of the plant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a 12-month-old plant of Heuchera ‘TNHEULS’ growing in a one gallon pot in a cold greenhouse in April in Canby, Oreg.

FIG. 2 shows 8-month-old plant of Heuchera ‘TNHEULS’ in October in the trial beds in full sun in Canby, Oreg.

DETAILED PLANT DESCRIPTION

The following is a detailed description of the new Heuchera cultivar based on observations taken in April of a 12-month-old specimen growing in a one gallon pot in a cold greenhouse in Canby, Oreg. Canby is Zone 8 on the USDA Hardiness map. Temperatures range from a high of 95° F. in August to an average of 32° F. in January. Normal rainfall in Canby is 42.8 inches per year. The color descriptions are all based on The Royal Horticultural Society Colour Chart, 5^(th) edition, 2007.

-   Plant:     -   -   Form.—Basal rosette, herbaceous perennial.         -   Hardiness.—USDA Zone 4 to 9.         -   Size.—12 cm tall from top of the foliage to the soil and 32             cm wide.         -   Number of crowns.—About 10.         -   Habit.—Medium-small, mounding.         -   Vigor.—Excellent. -   Leaf:     -   -   Type.—Simple.         -   Arrangement.—Rosette.         -   Shape.—Broadly ovate.         -   Number.—About 90.         -   Blade size.—Grows to 7.5 cm long and 7 cm wide.         -   Venation.—Palmate.         -   Lobing/Division.—4 shallow palmate lobes.         -   Leaf undulation.—Medium to weak.         -   Margins.—Broadly crenate.         -   Apex.—Mucronulate.         -   Base.—Cordate, usually overlapping.         -   Surface texture.—Topside sparsely glandular, bottom side             sparsely puberulent along veins.         -   Leaf rugosity.—Absent.         -   Petiole description.—Grows to 9.2 cm long and 5 mm wide,             glandular hairs, new petioles Greyed-Orange 166A and             Greyed-Red 181B, older petioles between Yellow-Green 152B             and Yellow-Green 148B.         -   Leaf color.—Spring color; topside Yellow-Green 144B and             Green 141C, veil with veins Greyed-Orange 166B, bottom side             closest to Green 139D, summer and fall color; mature leaves             or leaves in high light closest to a blend of Yellow 9C and             Yellow Green 1B, bottom side closest to Green Yellow 1C,             younger leaves or leaves in low light closest to a blend of             Yellow-Green 144B and Yellow 2B, bottom side closest to             Green Yellow 1B.         -   Leaf glossiness.—Weak. -   Inflorescence:     -   -   Size.—Grows to 10.5 cm wide and 15 cm long.         -   Type.—Upright thyrse.         -   Number of flowers per thyrse.—About 70.         -   Flower density.—Medium.         -   Number of thyrse.—About 10.         -   Flowering stem attitude.—Upright.         -   Peduncle.—Grows to 20 cm long and 4 mm wide at base,             glandular hairs, Greyed-Red 181C on bottom ⅓, blending to             Yellow-Green N144D on top ⅔.         -   Pedicel.—Grows to 5 mm long, with glandular hairs,             Greyed-Red 181C.         -   Bloom period.—Late April to mid-June in Canby, Oreg. -   Flower bud:     -   -   Size.—6 mm wide and 4.5 mm long.         -   Description.—Glandular puberulent, ovoid, down facing,             Yellow-Green 145C on bottom blending to White 155A, tip             Red-Purple 63B. -   Flower:     -   -   Type.—Perfect.         -   Shape.—Campanulate.         -   Attitude.—Side and down-facing.         -   Size.—1 cm long and 8 mm wide.         -   Corolla description.—5 petals, each 3.5 mm long and 1.5 mm             wide, spatulate, margins entire, tip acute, glabrous on both             sides, White NN155B on both sides.         -   Calyx description.—Campanulate, 1 cm long and 8 mm wide, 5             lobes with sinuses divided ½ way to the base, each 4 mm wide             and 5 mm long, ovate in shape, inside and back side             glandular-puberulent, tip obtuse, margin entire, outside             color Yellow-Green 145C on bottom ½ blending to White NN155A             on top ½, tip Red-Purple 63B, inside White NN155A.         -   Stamen description.—5 in number, filaments 2 mm long, White             155A, anthers 1 mm long, Greyed-Orange 163A, pollen none.         -   Pistil description.—1, 2-beaked, 4.5 mm long and 2 mm wide,             ovary 2 mm long and 2 mm wide, White 155A, style 2 mm long,             White 155A.         -   Fragrance.—None.         -   Lastingness.—Each thyrse blooms for about 3 weeks on the             plant. -   Fruit and seed: None seen. -   Pest and disease tolerance: The new cultivar is typical to the     genus. No known resistances to pests or diseases. No problems have     been found in Canby, Oreg. 

I claim:
 1. A new and distinct Heuchera plant as herein illustrated and described. 